With application software, a desired processing can be executed by inputting a command through either a keyboard or a mouse. It is assumed in the following description, for instance, that one of the lines in a text prepared by a word processor is to be deleted with a key operation. Generally, the line is deleted by executing the operations of displaying a menu, selecting a command "delete", further selecting a command "a unit of line", and specifying the line to be deleted. On the other hand, a system in which a command is selected from the menu requires a number of key strokes. Thus, shortcut keys are prepared in the application for inputting commands with a fewer number of key strokes than that in the ordinary mode. By using these shortcut keys, a line can be deleted with one operation, for instance, of pressing down a delete key while a shift key is pressed down.
Also when a command is to be input using a mouse, there are prepared two types of inputting systems: a menu system in which a desired processing is executed by successively selecting each command from the menu, and a shortcut inputting system in which a command can be executed with one operation, like the shortcut keys, by clicking a button or the like displayed on a screen.
However, when a command is to be input with the shortcut keys, it is required to remember a different set of key operations for each application software because keys allocated to commands are different in each application.
Also when a command is to be input by clicking a button or the like displayed on a screen with a mouse, the display format of buttons or the like is different in each application software. Thus, an operator has to remember various mappings between buttons and commands for each application software. Also, when inputting characters using a keyboard, the operator has to move his (her) hand off the keyboard to operate a mouse, which prevents high-speed operations for inputting characters.